不同淹水方式对花叶假连翘生长和生理的影响

为探究不同淹水方式对中生植物花叶假连翘形态、生长和生理特征的影响,了解花叶假连翘对淹水的响应机制,为拓展其应用范围,更好地发挥其景观、经济和生态价值提供科学的理论依据。采用盆栽淹水法,设置低水位间歇淹水（A）、低水位连续淹水（B）、高水位连续淹水（C）3种处理,同时设置对照（CK）,连续试验70 d,观察各处理组植物的形态变化、测定其生长和生理指标。结果显示：处理A、B的花叶假连翘植株存活率均为100%,茎基形成肥大皮孔和不定根,叶片形态与CK无显著差异。处理A的植株地上部分生长受到明显促进,株高和生物量均显著高于CK,地上部分生物量与CK无显著差异,可溶性蛋白（SP）含量无明显变化。超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）等抗氧化酶活性和丙二醛（MDA）含量、游离脯氨酸（Pro）含量呈先上升后下降的变化趋势,并逐渐趋于CK。处理B的花叶假连翘植株地上部分生长受到显著抑制,株高和地上部分生物量均显著低于CK和处理A,地下部分生物量显著增加。SP含量呈下降趋势,70 d时显著低于CK。MDA含量呈波动变化,抗氧化酶活性和Pro含量呈先上升后下降的变化趋势,70 d时MDA含量和Pro含量显著高于CK,抗氧化酶活性逐渐趋于CK的水平。处理C的植株淹水期间无不定根生成,生长受到严重抑制,各生理指标失去调节能力,32 d时全部死亡。因此,花叶假连翘对淹水较敏感,耐淹能力较强,可耐受14 d以内的高水位淹水,超出这个时长则无法存活;可长期适应低水位淹水。低水位淹水可以诱导花叶假连翘形成不定根,低水位间歇淹水对其生长有促进作用,低水位连续淹水则会抑制其生长。综上所述,花叶假连翘可应用于低影响开发城市雨洪管理建设中,在海绵城市、雨水花园、人工湿地中发挥其景观生态价值。

Effects of Different Waterlogging Methods to Growth and Physiology of Duranta repens ‘Variegata’

The study was aimed to explore the effects of different waterlogging methods on the morphology, growth and physiological characteristics of Duranta repens ‘Variegata’, and to understand the response mechanism of D. repens ‘Variegata’ to waterlogging, and to provide scientific theoretical basis for expanding its application range and better exploiting their landscape, economic and ecological values. In this study, the pot waterlogging method and three distinct treatments: intermittent low waterlogging (treatment A), continuous low waterlogging (treatment B), continuous high waterlogging (treatment C) and the control group (CK) were used. The test was lasted for for 70 days. The morphological changes of plants in each treatment group were observed, the growth and physiological indexes were measured. The survival rate of the four plants was 100% under the treatment of A and B, and the aerenchyma such as adventitious roots and hypertrophic dermis could be formed, and the leaf morphology was not significantly different from that of CK. In treatment A, the plant height and aboveground biomass of D. repens ‘Variegata’ significantly increased, but the underground biomass had no significant change. The content of soluble protein (SP) had no significant change. The content of malondialdehyde (MDA) and the activity of antioxidant enzymes (SOD, POD and CAT) increased first and then decreased, and gradually tended to the level of CK. In treatment B, the aboveground growth of D. repens ‘Variegata’ was significantly inhibited, the plant height and aboveground biomass were significantly lower than those of CK and treatment A, and the underground biomass significantly increased. The SP content showed a downward trend, which was significantly lower than that of CK at 70 days. The MDA content fluctuated, antioxidant enzyme activity and PRO content increased and then decreased. At 70 days, The content of MDA and PRO was significantly higher than that of CK, and the antioxidant enzyme activity gradually tended to the level of CK. In treatment C there was no adventitious root formation during waterlogging, the growth was seriously inhibited, and the physiological indexes lost ability to regulate, and all died at 32 days. Therefore, D. repens ‘Variegata’ can withstand short-term (within 14 days) high waterlogging, beyond which it cannot survive. Under low waterlogging stress, the morphological, growth and physiological changes can enhance the waterlogging tolerance and gradually adapt to the waterlogging environment. To sum up, D. repens ‘Variegata’can be applied to the construction of rainwater and flood management in low impact development cities, and give full play to its landscape ecological value in sponge cities, rainwater gardens and constructed wetlands.